In Detail: Solaris @one-north
by Foo E-Jin
SOLARIS is a 15 storey multi-tenanted facility for infocomms, media, science, engineering research and clean-tech development at one-north. Sited within Fusionopolis in the one-north Masterplan, the building is the winning project in a JTC competition to design, build and develop this facility. The design, completed in collaboration with TR Hamzah & Yeang, has been certified BCA Green Mark Platinum, the highest possible green certification granted by Singapore’s sustainable building benchmark. The building’s overall energy consumption represents a reduction of over 36% as compared to local precedents. With over 8,000 m2 of landscaping, Solaris also introduces vegetation which exceeds the area of the building’s original site. This green eco-infrastructure replaces the site’s original green footprint by 113%.
Fusionopolis is an integral part of the larger one-north masterplan that is developed by JTC. Together with the adjacent Biopolis and Mediapolis land parcels, the three entities within one-north aim to become incubators for biomedical research, new media production and high-tech software engineering development in Singapore and in South East Asia.
Perimeter Landscape Spiral Ramp
The key architectural element is an uninterrupted 1.5 km long ecological armature that connects the adjacent one-north Park at ground level and the basement Eco-cell with the cascading sequence of roof gardens at the building’s highest levels.
The continuity of the landscaping is a key component of the project’s ecological design concept as it allows for fluid movement of organisms and plant species between all vegetated areas within the building, enhancing biodiversity and contributing to the overall health of these ecosystems. The ramp, with its deep overhangs and large concentrations of shade plants, represents a key element in the comprehensive strategy for the ambient cooling of the building facade. This eco-infrastructure provides social, interactive and creative environments for the occupants of the building, while balancing the inherent inorganicness of the built form with a more organic mass. With its extensive eco-infrastructure, sustainable design features and innovative vertical green concept, Solaris strives to enhance the existing ecosystems at the site, rather than replace them.
Naturally Ventilated Spaces
Computational Fluid Dynamics (CFD) simulations carried out at the atrium led to the provision of an actuated skylight louvre system that allows for stack effect ventilation during hot days. Warm air escapes at the top, drawing in a continuous draft of cool air into the building at the ground level, providing thermal comfort to the occupants at the atrium without excessive use of active energy sources. A series of rainscreens fitted at the atrium ground floor entrances filter away wind-driving rain while allowing air movement to persist even during adverse weather conditions.
Skylight / Actuated Smoke Vent Louvres
The skylight louvre system at the top of the atrium serves another purpose besides allowing for the stack effect. It is a fail-safe system – upon the detection of fire within or near its proximity (via the building’s intelligent management system), the skylight louvres will automatically open up to disperse potential smoke or heat build-up due to the fire. This fail-safe smoke vent system will function even without the building’s main power supply, in case the latter is damaged by fire. This strategy eliminates the requirement of costly and power hungry engineering smoke control systems, which is commonly used in conventional atrium design.
In addition, the louvre system is designed to close during adverse weather to shield the occupants from rain via an array of rain detection sensors. There is a master override system to the signal transmitted by the rain sensor to ensure that the louvres revert to their open position in the event of fire.
A diagonal shaft that punctures through the largest floor plate allows daylight to penetrate deep into the building’s interior. Internal lighting operates on a system of sensors which reduces energy use by automatically turning off lights when adequate daylighting is available. Landscaped terraces within the solar shaft bring added quality to adjacent spaces and enhance views up into the building from the street below.
The final effect is the creation of refreshingly new high-rise office interiors overlooking trees and butterflies from the spiral green, enhanced by ambient mood lighting that constantly changes with the play of sunlight and shadow.
Residing at the building’s northeast corner, the Eco-Cell is the termination point of the spiral ramp. Puncturing the basement carpark levels, it brings light and natural ventilation into the subterranean levels. This feature is an integral part of the bioswale system that captures rainwater from the rooftop for irrigation purposes.
Rainwater Harvesting System
The building’s extensive landscaped areas are irrigated via a large scale rainwater recycling system. Rainwater is collected from the landscape areas via a network of siphonic drainage systems. The harvested rainwater is stored in a primary holding tank at the lowest basement level beneath the Eco-cell, and in small transfer tanks on the rooftops. A combined storage capacity of over 400 m³ allows the building’s vegetated areas to be irrigated almost exclusively via harvested rainwater. An integrated fertigation system helps maintain organic nutrient levels throughout the irrigation cycle for the vegetation in the entire building.
Climatic-Responsive Facade System
The project’s climate-responsive façade design originated with the analysis of the local sun-path. Singapore is at the equator, and the sun-path is almost exactly east-west. Facade studies based on the solar path were used to determine the shape and depth of the sunshade louvers, which also double as light shelves.
The sunshade louvres or light shelves are designed to screen off direct glare and heat from the sun, yet permit gentle daylight to filter into the building’s interior spaces. By allowing more natural daylight to enter the building interior, the need for artificial lighting during the day is significantly reduced. A network of light sensors is installed along the perimeter of all tenancy units. Once these sensors detect an external luminance of 500 lux and above, they automatically power down the fluorescent light fixtures located near the external glazed curtain wall.
The solar shading strategy also further reduces heat transfer across the building’s low-e double-glazed perimeter curtain wall, contributing to a low overall External Thermal Transfer Value (ETTV) of less than 40 W/m2. In conjunction with the spiral landscaped ramp, sky gardens, and deep overhangs, the sunshade louvres assist in establishing comfortable microclimates in the habitable spaces along the building’s exterior. The combined linear length of the building’s sunshade louvres exceeds 10km. These louvres are ‘lifted’ at strategic locations to reveal high volume entrances and sky terrace activity areas.
Planter Box Design on Landscaped Spiral Ramp
The landscaped spiral ramp has a minimum width of 3 meters. Maintenance of the spiral ramp is achieved via a parallel pathway which allows for servicing of the continuous planters without requiring access from the building’s internal tenanted spaces. The pathway is also designed to serve as a linear park that stretches all the way from the ground plane to the uppermost roof areas.
To keep the building facade elegant, the planter boxes on the spiral ramp are designed to be as shallow as possible, to reduce the “bulkiness” they would otherwise create when viewed from the exterior. The lack of deep soil means that the plant species had to be carefully selected to ensure that their roots are able to spread horizontally, instead of digging deep downwards for stability.
The planter boxes are typically only 800mm deep. An elaborate network of drainage trenches and subsoil pipes ensures effective water discharge even in the worst case scenario of a heavy downpour. This is important as the landscaped ramp is steeply inclined, and rainwater would cascade down at high speed on the surface level if it is not absorbed by the soil fast enough.
Roof Gardens and Corner Sky Terraces
Vertical landscaping acts as a thermal buffer and creates areas for event spaces, relaxation and spontaneous social activities. These extensive gardens allow for interaction between the building’s occupants and nature, offering opportunities to experience the external environment and enjoy views of the treetops of adjacent one-north Park. The sum of the building’s vegetated areas exceeds the footprint of the site on which the building sits. A dramatic vision of the possibilities inherent in skyrise greenery design, 95% of the project’s total landscaped area is above ground level.♦
Images: TR Hamzah & Yeang/CPG Consultants